What does errno 45 (EDEADLK) in Solaris mean?

EDEADLK

Deadlock detection in locks and synchronization

EDEADLK is Solaris errno 45 (Deadlock condition.). Solaris detected or avoided a deadlock in locking or synchronization.

Capture the lock order and the resources already held by the failing thread or process. The useful fix is to remove the cycle or use the documented locking order, not to increase timeouts around the same conflicting acquisition sequence.

What to check

• Record the lock type: fcntl record lock, mutex, semaphore, condition variable, or reader/writer lock.
• Inspect lock ordering and ownership rather than increasing timeout values.
• Compare with EDEADLOCK, which is an older Solaris alias-style spelling for file-locking deadlock reports.

References

• Oracle Solaris intro(2): error numbers
• illumos errno.h definitions
• POSIX errno.h